[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.313653][ T25] audit: type=1800 audit(1572869067.964:25): pid=7036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.333557][ T25] audit: type=1800 audit(1572869067.964:26): pid=7036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.403423][ T25] audit: type=1800 audit(1572869068.054:27): pid=7036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.57' (ECDSA) to the list of known hosts. 2019/11/04 12:04:38 fuzzer started 2019/11/04 12:04:39 dialing manager at 10.128.0.105:43623 2019/11/04 12:04:39 syscalls: 2553 2019/11/04 12:04:39 code coverage: enabled 2019/11/04 12:04:39 comparison tracing: enabled 2019/11/04 12:04:39 extra coverage: extra coverage is not supported by the kernel 2019/11/04 12:04:39 setuid sandbox: enabled 2019/11/04 12:04:39 namespace sandbox: enabled 2019/11/04 12:04:39 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/04 12:04:39 fault injection: enabled 2019/11/04 12:04:39 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/04 12:04:39 net packet injection: enabled 2019/11/04 12:04:39 net device setup: enabled 2019/11/04 12:04:39 concurrency sanitizer: enabled 2019/11/04 12:04:39 devlink PCI setup: PCI device 0000:00:10.0 is not available 2019/11/04 12:04:40 adding functions to KCSAN blacklist: 'generic_permission' 'tomoyo_supervisor' 'pipe_poll' '__hrtimer_run_queues' 'find_next_bit' 'generic_fillattr' syzkaller login: [ 47.696946][ T7195] ================================================================== [ 47.705081][ T7195] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 47.713031][ T7195] [ 47.715338][ T7195] write to 0xffff8881233332ec of 4 bytes by interrupt on cpu 0: [ 47.722949][ T7195] tcp_add_backlog+0x4a0/0xcc0 [ 47.727828][ T7195] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.732309][ T7195] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.737653][ T7195] ip_local_deliver_finish+0x110/0x140 [ 47.743086][ T7195] ip_local_deliver+0x133/0x210 [ 47.747908][ T7195] ip_rcv_finish+0x121/0x160 [ 47.752470][ T7195] ip_rcv+0x18f/0x1a0 [ 47.756555][ T7195] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.762249][ T7195] __netif_receive_skb+0x37/0xf0 [ 47.767200][ T7195] netif_receive_skb_internal+0x59/0x190 [ 47.772806][ T7195] napi_gro_receive+0x28f/0x330 [ 47.777773][ T7195] receive_buf+0x284/0x30b0 [ 47.782253][ T7195] virtnet_poll+0x436/0x7d0 [ 47.786744][ T7195] net_rx_action+0x3ae/0xa90 [ 47.791301][ T7195] [ 47.793715][ T7195] read to 0xffff8881233332ec of 4 bytes by task 7195 on cpu 1: [ 47.801231][ T7195] tcp_grow_window.isra.0+0x6b/0x480 [ 47.806493][ T7195] tcp_event_data_recv+0x68f/0x990 [ 47.811583][ T7195] tcp_rcv_established+0xbfe/0xf50 [ 47.816681][ T7195] tcp_v4_do_rcv+0x381/0x4e0 [ 47.821300][ T7195] __release_sock+0x135/0x1e0 [ 47.825950][ T7195] release_sock+0x61/0x160 [ 47.830342][ T7195] tcp_recvmsg+0x63b/0x1a30 [ 47.834819][ T7195] inet_recvmsg+0xbb/0x250 [ 47.839251][ T7195] sock_recvmsg+0x92/0xb0 [ 47.843554][ T7195] sock_read_iter+0x15f/0x1e0 [ 47.848254][ T7195] new_sync_read+0x389/0x4f0 [ 47.852934][ T7195] __vfs_read+0xb1/0xc0 [ 47.857062][ T7195] vfs_read+0x143/0x2c0 [ 47.861183][ T7195] [ 47.863483][ T7195] Reported by Kernel Concurrency Sanitizer on: [ 47.869650][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.877109][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.887139][ T7195] ================================================================== [ 47.895173][ T7195] Kernel panic - not syncing: panic_on_warn set ... [ 47.901848][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.909274][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.919347][ T7195] Call Trace: [ 47.922634][ T7195] dump_stack+0xf5/0x159 [ 47.926868][ T7195] panic+0x210/0x640 [ 47.930745][ T7195] ? sock_recvmsg+0x92/0xb0 [ 47.935226][ T7195] ? vprintk_func+0x8d/0x140 [ 47.939796][ T7195] kcsan_report.cold+0xc/0x10 [ 47.944458][ T7195] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.949985][ T7195] __tsan_read4+0x2c/0x30 [ 47.954293][ T7195] tcp_grow_window.isra.0+0x6b/0x480 [ 47.959586][ T7195] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.965201][ T7195] tcp_event_data_recv+0x68f/0x990 [ 47.970291][ T7195] tcp_rcv_established+0xbfe/0xf50 [ 47.975731][ T7195] ? ipv4_dst_check+0xc6/0xf0 [ 47.980405][ T7195] tcp_v4_do_rcv+0x381/0x4e0 [ 47.984988][ T7195] __release_sock+0x135/0x1e0 [ 47.989652][ T7195] release_sock+0x61/0x160 [ 47.994231][ T7195] tcp_recvmsg+0x63b/0x1a30 [ 47.998719][ T7195] inet_recvmsg+0xbb/0x250 [ 48.003112][ T7195] ? __tsan_read8+0x2c/0x30 [ 48.007606][ T7195] ? inet_sendpage+0x100/0x100 [ 48.012346][ T7195] sock_recvmsg+0x92/0xb0 [ 48.016654][ T7195] sock_read_iter+0x15f/0x1e0 [ 48.021322][ T7195] new_sync_read+0x389/0x4f0 [ 48.025894][ T7195] __vfs_read+0xb1/0xc0 [ 48.030027][ T7195] vfs_read+0x143/0x2c0 [ 48.034157][ T7195] ksys_read+0xd5/0x1b0 [ 48.038290][ T7195] __x64_sys_read+0x4c/0x60 [ 48.042775][ T7195] do_syscall_64+0xcc/0x370 [ 48.047257][ T7195] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.053122][ T7195] RIP: 0033:0x47c530 [ 48.056995][ T7195] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 48.076694][ T7195] RSP: 002b:000000c4204f7810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 48.085080][ T7195] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.093025][ T7195] RDX: 0000000000001000 RSI: 000000c4203fc000 RDI: 0000000000000003 [ 48.101058][ T7195] RBP: 000000c4204f7868 R08: 0000000000000000 R09: 0000000000000000 [ 48.109005][ T7195] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 [ 48.116951][ T7195] R13: 000000c42007f640 R14: 0000000000000002 R15: ffffffffffffffff [ 48.126186][ T7195] Kernel Offset: disabled [ 48.130507][ T7195] Rebooting in 86400 seconds..